Corn Starch Content Research Articles

Starch consolidation of SiC ceramics: processing and low-temperature sintering in an air atmosphere

ABSTRACTHighly porous SiC ceramics containing borax decahydrate were produced by a starch consolidation method in which corn starch was used as a shaping and pore-forming additive. Four different compositions were prepared with different SiC:borax decahydrate ratios and corn starch content. Mixtures with a solid ratio of 55 wt.% were cast in non-porous molds and heated at 80°C for shaping. The starch consolidation technique enabled the shaping of SiC ceramics with different forms and sizes. Simultaneous thermogravimetry and differential thermal analysis of the SiC-borax decahydrate mixture showed that melting took place at below 600°C, as a result of which sintering was carried out at the relatively low temperature, of 600°C in the air using borax decahydrate as a sintering additive. Phase analysis showed that oxidation of SiC did not take place, since no cristobalite phase was detected. Density measurement and mercury porosimetry studies showed that highly porous (70–89% porosity) SiC ceramics with pore size values ranging from 14 to 18 μm were produced. SEM microstructures of each composition revealed that a strong neck had been formed between the SiC particles in spite of the low sintering temperature.

Chemical characteristics of brownis substituted with sago starch and corn starch

Sago (Metroxylon sp) is a native plant to southeast Asia, and is one a food commodities that contain a lot of carbohydrated. Therefore, sago is used as a staple food for several regions in Indonesia such as Maluku and Irian Jaya. In the sago community, there is very little use of sago, even though sago can be used as raw material for making various products such as noodles, cakes, cookies, crackers and brownies. The study aimed to determine the effect of substitutions of sago starch and corn starch on the chemical properties of brownies. This study used factorial Completely Randomized Design which consisted of two factors. The first factor was the percentage of sago starch (S), which consisted of 3 levels, namely S1 = 50%, S2 = 75%, and S3 = 100%. The second factor was the concentration of corn starch (T) which consisted of 2 levels, namely T1 = 15% and T2 = 20%. The parameters observed werewater content, ash content, fiber content, fat content, protein content, and carbohydrate content. The best treatment for chemical test is on the T2S2 treatment with the results of water content of 23.62%, ash content 2.14%, fiber content 3.46%, fat content of 23.95%, protein content of 3.36%, and carbohydrates 50.15%.

Influence of cornstarch on thermomechanical behavior of poly(vinyl) chloride bioplastics

ABSTRACTThe diverse and ubiquitous consumption of polymers urges the necessity to make these materials easily available. However, the excessively used petrochemical‐based polymers such as poly(vinyl) chloride (PVC) are nonbiodegradable, which is a motivation to modify it with “green” alternatives. In the present study, PVC (Mw = 48 000 g mol−1) has been incorporated with cornstarch (CS) to synthesize a series of 25 samples of bioplastics in addition to blank polymer samples. The films of five various thicknesses (0.1, 0.2, 0.3, 0.5, and 1.0 mm) have been synthesized using in situ polymerization. Each sample of pure PVC film and bioplastic has been induced with different concentrations of CS in the range of 1–5 wt %. The synthesized samples were subjected to the structural characterization by using Fourier transform infrared. Thermogravimetric analysis has demonstrated the three‐step degradation with the improved stability of 250 °C. The 3% concentration of CS has shown the optimum storage modulus (E′) of 1 660 MPa from dynamic mechanical analysis and Tan δ as 0.50. The swelling test performed using water has shown an induction of hydrophilicity in PVC up to 4%. CS‐induced bioplastics can be a potential ecofriendly alternative of conventional polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48493.

Effect of extrusion cooking on physicochemical properties of tuna meat-based extrudates

Abstract Effect of extrusion cooking using different corn starch contents on the physicochemical properties (expansion ratio, bulk density, color, hardness, protein in vitro digestibility, crude protein content, thermal properties and microstructure) of tuna meat-based extrudates was investigated. The results showed that the increased corn starch content led to darker, greener, yellower and lower crude protein content of extrudates, but no significant difference was observed in expansion ratio, bulk density and hardness. The lowest protein in vitro digestibility of 82.83±0.39% appeared when the corn starch content was 20 wt%. The results of DSC revealed that tuna meat with corn starch content of 30 wt% and 20 wt% had the highest and lowest denaturation temperature of 99.4oC and 81.9 oC, respectively. The results of SEM indicated that the extrudate with 30 wt% corn starch content possessed the more integrated and distinct muscle fibers. Besides, the acceptability of the extrudate with 30 wt% corn starch content was significant better than others (p˂0.05). These results revealed that the tuna meat-based extrudates using 30 wt% of corn starch exhibited desirable physicochemical properties.

Changes in physicochemical properties of pork myofibrillar protein combined with corn starch and application to low‐fat pork patties

SummaryThe aim of this study was to evaluate the physicochemical properties of pork myofibrillar protein (MP) gels as affected by different additional levels of corn starch and microbial transglutaminase (MTGase) and applied to pork patties at two levels of corn starch. MPs with MTGase have higher properties than those without MTGase, except cooking loss (CL), which improved with higher corn starch concentrations. Although gel strength did not differ among the treatments, microstructures of corn starch were swollen, which proved that they were holding water. When corn starch was added, CL and thawing loss decreased, but shear value increased. The diameter shrinkage values of pork patties decreased with increasing corn starch concentrations. In addition, the pork patties with 2 g/100 g corn starch have a higher water‐holding capacity than the controls. The meat industry could use 1.0 g/100 g corn starch as a water‐binding agent to manufacture pork patties.

Nanocomposite films with silver nanoparticles synthesized in situ: Effect of corn starch content

The aim of this work was to analyze the effect of native corn starch content (1, 3 and 5% w/v) on the development of nanocomposite films with 143 ppm silver nanoparticles (AgNPs) synthesized in situ. The tested concentrations allowed synthesizing AgNPs in situ and suspensions maintained their filmogenic capacity, regardless the starch content. The characteristics of AgNPs were studied by spectrophotometric techniques, high-resolution transmission electron microscopy (HR-TEM) and zeta potential measurement, finding they are spherical with diameters between 19.9 and 13.4 nm and negatively charged. Films containing 1% starch, were difficult to handle coinciding with the mechanical profile obtained, which corresponds to a slightly ductile material. Nanocomposite films with 5% starch showed improved mechanical and barrier properties due to the increase of starch content, but they did not evidence a matrix reinforcement by the AgNPs incorporation. Furthermore, films containing 3% starch show the optimal mechanical and barrier properties, attributed to the reinforcement of AgNPs. Regarding the antimicrobial capacity, all nanocomposite films inhibited microorganisms’ growth. Thus, considering the obtained results nanocomposite films formulated with 3% starch were selected as the most suitable option for their application as food packaging.

High-performance macro-porous alumina-mullite ceramic membrane supports fabricated by employing coarse alumina and colloidal silica

Abstract Cost-effective porous alumina-mullite ceramic membrane supports were prepared from mixtures of different alumina/silica (Al2O3/SiO2) ratios of coarse α-alumina micro-powder and colloidal silica (CS). The effects of sintering temperature, Al2O3/SiO2 ratio and cornstarch content on the crystalline phase evolution, microstructures, porosity, bending strength, pore size distribution and permeance of the ceramic membrane supports were systematically investigated. The results showed that the increase in sintering temperature was beneficial to the mullite formation and the bending strength. However, it was adverse to the improvement of porosity and the pore size distribution which have positive correlation with the permeance of the supports. The increases in Al2O3/SiO2 ratio and cornstarch were favourable to the mullite formation, improvement of porosity, pore size distribution and morphology of the supports, but were unfavourable to the bending strength. A high-performance porous alumina-mullite ceramic support with suitable porosity (50.5%) and pore size (3.1 μm), sufficient mechanical strength (49.7 MPa) and high permeances was successfully synthesized by optimizing the sintering temperature, Al2O3/SiO2 ratio and cornstarch content. Moreover, the proposed simple method shows much potential for the preparation of high-performance porous alumina-mullite ceramic membrane supports.

Impact of flint corn processing method and dietary starch concentration on finishing performance of Nellore bulls

Nellore cattle are predominant in Brazil and appear to have poor performance when fed high-grain diets. In addition, most corn produced in Brazil is of the flint type, and the starch therein is more difficult to digest compared to that in dent corn hybrids. The aim of this study was to evaluate flint corn processing method (CPM) and dietary starch content for finishing Nellore bulls fed high-concentrate, corn-based diets. In this study, 112 Nellore bulls (initial BW 378.3 ± 21.28 kg) were fed twice daily using Calan gates or individual pens. The animals were used in a randomized complete block design with a 2 × 4 factorial arrangement of treatments. The experiment tested two CPM: high moisture corn (HMC) and finely ground dry corn (FGC) and dietary starch concentrations (DSC) of 300, 350, 400 and 450 g/kg DM, replacing citrus pulp with corn. Bulls were adapted to finishing diets over a period of 18 days and fed a total of 75 days (18 + 57 days). To determine fecal starch (FS) concentration, feces from each animal were sampled on day 47 of the feeding period. Bulls fed diets containing more than 300 g/kg DSC from HMC were more efficient than bulls fed 300 g/kg DSC as HMC; but gain:feed ratio (G:F) for bulls fed FGC did not differ (CPM × DSC; P = 0.04). Final BW and average daily gain (ADG) were not affected by CPM, but carcass G:F was greater for bulls fed HMC than for those fed FGC (P < 0.01). Increases in DSC resulted in quadratic decreases in DM intake (P = 0.02), linear decreases in metabolisable energy (ME) intake (P < 0.01), and linear improvements in carcass G:F (P < 0.01). Interactions between CPM and DSC were observed for calculated dietary concentrations of net energy for maintenance (NEm), net energy for gain (NEg), and ME (P = 0.02), whereby NEm, NEg and ME of diets increased linearly with increases in DSC for bulls fed HMC, but did not differ across DSC for bulls fed FGC. Bulls fed FGC had 2.75 times greater FS compared to bulls fed HMC (P < 0.01); resulting in lower fecal pH for bulls fed FGC compared to those fed HMC (P < 0.01). In conclusion, there was no effect on G:F of Nellore cattle or net energy content of diets when DSC was increased by adding flint FGC, but increasing HMC in diets improved growth efficiency and net energy content.

Improving the properties of straw biomass rattan by corn starch

ABSTRACT As a kind of renewable resource and natural biomass, starch has been widely used to substitute plastics in the modern industry and is regarded as one of the most promising biodegradable materials. The newly developmental rattan, straw biomass rattan (SBR) as weaving material, has been exploited as per our previous work, which possessed advantages of both natural rattan and pure plastic rattan. The main objective of the work was to improve the properties of SBR by corn starch (CS). Based on the manufacturing of the above composites, the experiments of SBR that enhanced with CS on mechanical properties, melting performance, hydroscopicity, thermogravimetric analysis, and microstructures were tested in this study. The results revealed that when the content of CS increased gradually within the range of 0, 3, 6, 9 12, and 15 wt.%, the mechanical properties and melt index of the composite both increased first and then decreased, with 6 to 12 wt.% as the optimal dosage range. In contrast, the water absorption of SBR kept increased in this range, indicating an easier biodegradable. With CS added, the microstructure of SBR was examined by scanning electron microscope and found the microscopic surfaces and sections to become smoother, and that could improve the compatibility and tenacity between the materials. As a result, CS in moderation can be used as a supplement to enhance SBR, and improve their characteristics which will enhance the mechanical properties of the composites for future perspectives.

Effect of water content of high-amylose corn starch and glutinous rice starch combined with lipids on formation of starch-lipid complexes during deep-fat frying.

Moisture affects the combination of starch granules and fatty acids in deep-fat frying. In this study, high-amylose corn starch (HACS) and glutinous rice starch (GRS) with various water contents were fried in rapeseed oil at 170 °C for 7 min. The complex index (CI) of the GRS-lipid and HACS-lipid complexes improved as the moisture content increased from 6% to 40%; however, further increasing the water content from 40% to 60% led to a decrease in the CI. At a moisture content of 40%, the CI of the HACS-lipid complexes was higher than that of the GRS-lipid complexes. Fatty acid content analysis revealed that the total fatty acid content at different moisture contents in the HACS-lipid complexes was higher than that in the GRS-lipid complexes both before gelatinization and after enzyme hydrolysis. In addition, the total fatty acid content in the HACS-lipid complexes and GRS-lipid complexes at 40% moisture content was the highest among all the measured moisture contents. Scanning electron microscopy revealed that both the HACS and GRS granules lost their integrity after deep-fat frying, and no free lipid droplets were noted among the starch granules after defatting. Both Fourier-transform infrared spectroscopy and fluorescence microscopy verified that HACS combined with lipids yielded a stronger lipid-binding capacity than that of GRS at a moisture content of 40%. The study results may be potentially useful in the deep-fat frying of starchy food to produce foods with lower fatty acid content.

Characterization of edible coatings based on ripe “Prata” banana peel flour

To increase the useful life of food products, edible coatings were developed using flour made from ripe “Prata” banana (Musa spp.) peels and cornstarch, a low coast, water soluble, biodegradable natural polymer that facilitated the handling of films, and characterized as to their physical, mechanical, and barrier properties. The films were prepared from the banana peel flour by the casting technique, varying the cornstarch concentration (33.3–66.6% w/w) and the heating time (30–60 min). The effects of these two variables on the properties were evaluated by response surface methodology. For the physical properties, it was found that the thickness (0.059–0.085 mm) was influenced by increasing the cornstarch concentration. The chroma remained uniform with different cornstarch concentration and heating time. Whereas, the luminosity had an inverse behavior to the heating time. The solubility of the films were not related to the study variables. As for the barrier properties, water vapor permeability (8.85–14.82 × 10−5 g/m.s.Pa) of the films was influenced by the cornstarch concentration. The mechanical behavior presented low tensile strength values (0.14–0.70 MPa). The elastic modulus (3.00–33.08 MPa) had a direct relationship with the cornstarch concentration and heating time, but the elongation rates (9.84–20.16%) were influenced only by the heating time. The puncture test (5.56–20.01 MPa) was influenced by the variables, and the puncture deformation (9.05–30.13%) by the variables and their interaction. This study demonstrates that ripe “Prata” banana peel flour is a promising material to be used as a raw material to develop edible films.

Independent effects of dietary fat and sucrose content on chondrocyte metabolism and osteoarthritis pathology in mice.

ABSTRACTObesity is one of the most significant risk factors for knee osteoarthritis. However, therapeutic strategies to prevent or treat obesity-associated osteoarthritis are limited because of uncertainty about the etiology of disease, particularly with regard to metabolic factors. High-fat-diet-induced obese mice have become a widely used model for testing hypotheses about how obesity increases the risk of osteoarthritis, but progress has been limited by variation in disease severity, with some reports concluding that dietary treatment alone is insufficient to induce osteoarthritis in mice. We hypothesized that increased sucrose content of typical low-fat control diets contributes to osteoarthritis pathology and thus alters outcomes when evaluating the effects of a high-fat diet. We tested this hypothesis in male C57BL/6J mice by comparing the effects of purified diets that independently varied sucrose or fat content from 6 to 26 weeks of age. Outcomes included osteoarthritis pathology, serum metabolites, and cartilage gene and protein changes associated with cellular metabolism and stress-response pathways. We found that the relative content of sucrose versus cornstarch in low-fat iso-caloric purified diets caused substantial differences in serum metabolites, joint pathology, and cartilage metabolic and stress-response pathways, despite no differences in body mass or body fat. We also found that higher dietary fat increased fatty acid metabolic enzymes in cartilage. The findings indicate that the choice of control diets should be carefully considered in mouse osteoarthritis studies. Our study also indicates that altered cartilage metabolism might be a contributing factor to how diet and obesity increase the risk of osteoarthritis.

Corn, potato, and wrinkled pea starches with heat–moisture treatment: Structure and digestibility

AbstractBackground and objectivesStarches from corn, potato, and wrinkled pea were heat treated at 100 and 120°C for 12 hr at a moisture content of 25% to produce slowly digestible starches. The effect of heat–moisture treatment (HMT) on structure and digestibility of those starches was investigated.FindingsChanges in morphological aspects could be found in corn and pea starches after HMT treatment, potato starch retained its granular appearance with only some slight breakage of granules. For the HMT‐treated starches, the intensity of birefringence slightly decreased and the polarized cross also still existed. All the HMT starches showed the increasing To, Tp, and Tc and the decreasing enthalpy. The X‐ray diffraction pattern of potato and pea starches was shifted from B‐ or C‐type to A‐type by HMT, and corn starch changed to A + V‐ type. Compared with native starch, the relative crystallinity of starches decreased, and the degree of gelatinization of all starches was greater than that of their counterparts. After HMT, RDS and SDS contents of potato and pea starches (except corn starch) increased compared with their native counterparts, whereas RS content of all three starches was decreased. Compared with native starch, the digestibility of starches after HMT had a certain degree of increase.ConclusionsHeat–moisture treatment had different effects on the granules morphology of different starch. The HMT samples exhibited greater To, Tp, and Tc values than those of the native counterparts with regard to the three starch types. The crystal structure and crystal pattern were transformed to the A‐type by HMT. Corn starch was easier to gelatinize than potato starch and pea starch after HMT, which could be the lower amylose content of corn starch and a smaller proportion of long chain. With the increase of HMT temperature, the starch sample RDS and SDS contents increased and RS decreased.Significance and noveltyCorn starch was easier to gelatinize than potato starch and pea starch after HMT. With the increase in HMT temperature, the starch sample RDS and SDS contents increased and RS decreased.

Alumina Ceramics Fabricated by in-situ Consolidation of Pre-gelling Starch

An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, higher density, higher flexural strength, and favorable biocompatibility compared to the regular one. During the process, cornstarch granules swelled and deformed but no fracture was observed. After the cornstarch granules bursted, alumina particles were suspended uniformly in the three-dimensional network structure to generate a much smoother surface. Below 0.5 wt% higher cornstarch content increased the flexural strength of prepared ceramics, while above 0.5 wt% the mechanical properties were compromised. Therefore the cornstarch content of 0.5% was the optimal concentration to achieve the highest mechanical strength of the prepared ceramics, with a measured flexural strength of 341 MPa, and a relative density of 96.01%.

PENGARUH SUBSTITUSI TEPUNG JAGUNG (Zea mays L.) DALAM PEMBUATAN COOKIES

The study aims to determine the effect of substitution of corn flour in the production of cookies and cookies hedonic test results. Research carried out two stages. The first stage, the process of making corn flour. The second stage, of making cookies with concentration of wheat flour (100 g, 85 g, 80 g, 75 g) and cornstarch (0 g, 15 g, 20 g, 25 g). This study uses a completely randomized design (CRD), which consists of a single factor, namely the concentration of cornstarch 0 g, 15 g, 20 g and 25 g. Data were analyzed using analysis of variance (ANOVA) followed by a further test DMRT. In all aspects of testing the color, flavor, aroma and texture have F count> F table means that there is a real difference in each sample cookies experimental results. The results showed that the concentration of cornstarch similar in chemical quality of the water content of cookies as cookies. Cookies are most preferred treatment concentration C (25 g)

Effects of Corn Starch and Kappaphycus alvarezii Seaweed Blend Concentration on the Optical, Mechanical, and Water Vapor Barrier Properties of Composite Films

Composite films with different Kappaphycus alvarezii seaweed and corn starch concentrations were developed, and the effect of these concentrations on the films’ optical, mechanical, and water vapor barrier properties were investigated. The chemical interactions between the two components in the film were verified by chemical composition and Fourier transform infrared (FTIR) spectroscopy investigations. The results showed that the mechanical properties and opacity of the composite films were enhanced with the addition of seaweed. Among the compositions, a composite film with 3% seaweed and 1% starch exhibited the highest tensile strength and elongation at break. The water vapor permeability (WVP) of the composite films linearly increased with the increments of starch and seaweed concentrations. The FTIR analysis also revealed intermolecular interactions between the two components, consistent with the good miscibility of seaweed and starch in the blend. Therefore, different concentrations of the blend of seaweed and starch could be used to tailor a film with certain desired functional properties.

Amylolysis is predominated by cell-surface-bound hydrolase during anaerobic fermentation under mesophilic conditions

While knowing the amylolysis mechanism is important to effectively decompose corn starch fed into an anaerobic digestor, the objective of this study was to detect the activities and locations of α-amylase in a continuous reactor and batch cultures. In the continuous reactor operated at 35°C, the greatest cell-bound α-amylase activity was found to be 4.7 CU mL-1at hydraulic retention time (HRT)=9h, while the greatest volumetric hydrogen production rate (rH2) was observed at HRT=3h as 61mmolL-1 day-1. In the batch tests, the cell-bound α-amylase activities increased when the carbohydrate concentration decreased, and no significant reducing sugar accumulation was found in the serum bottles. By examining the specific hydrogen production rate (qH2) against different corn starch concentrations, the half-saturation constant (KSta) and the maximum qH2 were regressed to be 0.47gL-1 and 6mmol g-VSS-1d-1, respectively. The electronic microscopic images showed that the microbes could colonize on the starch granules without the disturbance of any floc-like materials. Conclusively, by excluding the methanogens and floc matrix, the secreted α-amylases are predominately bound on the cell surfaces and enabled the microbial cells favorably attach on large substrates for hydrolysis under the mesophilic condition.

Influence of starch content on the properties of low cost microfiltration membranes

This study is related to the development of low cost microfiltration (MF) membranes using cheap raw materials, namely clay and corn starch. Flat MF membranes were prepared by uniaxial dry pressing and sintered at firing temperature of 950 °C. Microstructure, porosity, permeability, shrinkage and flexural strength of the elaborated MF membranes were studied as function of corn starch content (0–20 wt.%). The experimental results indicated that the porosity and permeability of MF membranes increased with the increasing of corn starch content. However the flexural strength reduced from 16.3 to 10 MPa with the increasing of corn starch content from 0 to 20 wt.%. Moreover the addition of corn starch had no significant effect on the linear shrinkage. Elaborated MF membranes were used to treat wastewater from textile industry. The filtration results showed that the turbidity retention decreased with the increasing of corn starch content and all the turbidity retention values were greater than 80%. MF membranes with a satisfied porosity, permeability and mechanical strength were elaborated with the addition of 10 wt.% of corn starch.

The development of banana peel/corn starch bioplastic film: a preliminary study

The aim of this study is to develop bioplastic film from a combination of two biopolymers of same source, namely banana peel and corn starch. Five banana peel films (BP film) were prepared with different concentrations of corn starch (1% up to 5%) as co-biopolymer and film without corn starch acted as a control. The films were carried out with several durability tests and characterization analyses. Based on the results obtained, the BP film with 4% corn starch gave the highest tensile strength 34.72 N/m2 compared to other samples. The water absorption test showed that BP films with 3% corn starch were resistant to water uptake by absorbing water up to 60.65%. In terms of characterization, spectra of Fourier Transform Infrared Spectroscopy (FTIR) obtained for BP control film and BP film with 4% corn starch were comparable with most of the peaks were present. The thermal analysis by differential screening calorimetric (DSC) detected the melting temperature for both BP control film and BP film with 4% corn respectively at Tonset of 54.41°C and 67.83°C. Overall, combination of starches from two different sources can be used as an alternative in producing bioplastics.

NMR relaxometry as a tool to understand the effect of microwave heating on starch-water interactions and gelatinization behavior

Starch-water interactions during gelatinization by microwave heating was investigated by Low-field 1H Nuclear Magnetic Resonance (LF NMR) relaxometry experiments. Effect of microwave heating time on longitudinal (T1) and transverse relaxation times (T2), gel matrix structures, changes in proton populations and firmness values were evaluated. One to one corn starch (CS) to water ratio samples had the lowest T2 change during gelatinization indicating lower granule expansion which was attributed to the high amylose content of CS. Non-Negative-Least-Square (NNLS) analysis of the transverse relaxation curves provided detailed information on starch-water interactions during gelatinization. Rice starch (RS) samples had relatively lower changes in peak areas which was related to the better hydration of RS granules. While microscope images revealed the changes in the granule structures after distinct gelatinization intervals, firmness measurements supported the structural changes. With increasing microwave heating time, both T1 and T2 showed a decreasing trend. Two distinct proton populations detected on relaxation spectrum indicated the exchanging protons during gelatinization. A noticeable reduction in firmness at the later moments of microwave heating was detected. The results showed that starch gelatinization by microwave heating had some distinct features in terms of mechanism of the gelatinization and could be investigated by NMR relaxometry.